asquith, saskatchewanThe carbon monoxide incident happened near Asquith, about 34 kilometres west of Saskatoon.

A man, 29, is dead and a woman, 26, is in hospital following a carbon monoxide leak at a home near Asquith, Sask.

The two were found in the home Monday morning around 7:30 a.m. CST after a family member went to check on them.

Both were unconscious, but only the woman was still alive. The carbon monoxide in the home was at a lethal level, police said.

The woman was taken to Royal University Hospital in Saskatoon in serious condition.

Police said a furnace boiler is believed to be the source of the poisonous CO gas.

The names of the man and woman haven't been released. CBC News has been told that the couple was engaged to be married.

But that wasn't the only carbon monoxide poisoning incident Tuesday morning. 

Three other people from the Little Red First Nation were taken to hospital as a precaution after a faulty space heater started leaking carbon monoxide in their home.

There were 19 carbon monoxide calls over the weekend, which Sask Energy said is about average.

The utility company said it usually responds to about 1,100 per year, mostly in the winter month.